Driving mechanism for plate-printing machines.



0. ROESEN.

DRIVING MECHANISM FOR PLATE PRINTING MACHINES.

APPLICATION FILED NOV. I2. I915.

Patented Jan. 15, 1918.

LQ5EAQQI DSCA-lt EOESEN, OF-NEW YORK, N. '31, A-ESIGNOR TO B. HOE AND 06., OF NEW YURK,

' i N. Y., A CORPORATION 03*? NEW YORK.

DRIVING MECHANISM FC'R PLATE-PRINTING MACHINES.

Specification of Letters Patent.

Patented Jan. 15, 1918..

Application filed November 12, 1915. Serial No. 61,032.

York city, county of New York, and State of New York, have invented certain new and useful Improvements 111 Driving Mechanism for Plate-Printing Machines, fully described and represented in the following specification and the accompanying drawings, form ing a part of the same.

This invention relates to certain improvements in plate printingmachines.

In plate printing machines the printingis done from a flat plate or other surfaces by means of depressed lines. To effect printing with these plates, the whole surface of the plate is first covered with ink so that the lines are effectually filled. The surface of the plate, however, where there are no lines, must be cleaned. To effect this, the plate is wiped in some manner, usually by an endless roll of cloth which is gradually renewed by suitable feeding mechanism. The plate or engraved surface is carried on a suitable support, such as a bed, with which cooperates, to effect the printing, an impression member, usually a cylinder or roll, which is provided with a blanket. To effect a clear impression, and to avoid blurring, the plate or other engraved surface and the cooperating impression member should run at the same speed. The speed of the cylinder, however, relatively to the bed, is, where the cylinder is positively driven, fixed by the diameter of the cylinder. As this cylinder is provided with a blanket, the diameter of the'cylinder will vary, and consequently the speed at which it is driven, this variance in diameter being due to overpacking the blanket, or to different thicknesses of the blanket, or because of the fact that after a blanket has been used it compresses and becomes thinner. lVhere this change in diameter of the cylinder occurs, the slight vari ance in speed of the cylinder relatively to the speed of its driving mechanism, thus compensatmg for the small variations 1n the diameter of the cylinder, due to the causes pointed out above.

F or a full understanding of the invention, reference may be had to the accompanying drawings, in which Figure 1 is an end view of so much of the impression portion of a plate printing machine as is necessary for an understanding of the invention;

Fig. 2 is a front view of the construction shown in Fig. 1; and

Fig.8 is a top view, partly in section, of the driving mechanism shown in Figs. 1 and 2.

The machine chosen to illustrate the preferred embodiment of the inventionis a plate printing machine in which the plate carrying member is a flat bed and the iml'iress on member is roll or cylinder, al-

though it will be understood that the improved driving mechanism may be employed in machines in which the plate carrying and impression members may take different forms.

' Referring to the drawings, 1 indicates a plate carrying bed and 2 a plate carried thereon. The plate carrying bed is a positively driven bed, the driving mechanism for which is of any suitable character, and a showing of which has been omitted for the sake of clearness and as being unnecessary for an understanding of the invention. C0- operating with this plate carrying bed is an impression member which in the particular construction shown is a cylinder 3 provided with the usual blanket & secured to the cylinder by the usual blanket clamps 5 supported in a slot 6 in the cylinder. This cylinder is mounted on a shaft 7 carried on the usual bearings 8 mounted in the frame of the machine 9. This cylinder is a positively driven cylinder, the power for driving the cylinder being obtained from any suitable source (not shown), this power being co1n municated to a driver shown as a sprocket wheel 10 mounted on the shaft 7 of the cylinder.

In machines embodying the invention, devices will be provided whereby the cylinder may rotate at a slightly increased or decreased speed relatively to the speed of the mechanism by which it is driven, so that the cylinder when it comes in contact with 7 driving heads 15.

the plate may roll with the plate at the same rate of speed at which the bed carrying the plate is moved. The specific means for effecting this may be varied. In the particular construction illustrated the driving sprocket 10 to which the driving power is communicated is loosely mounted on the cylinder shaft 7, and there are provided yielding connections between the sprocket and a driven member fixed on the cylinder shaft so that a slightly increased or decreased speed of the cylinder shaft relatively to the sprocket is provided. WVhile these connections may be somewhat varied, in the particular construction illustrated the sprocket 10 is provided with a pair of socketed ears 11, 12 in which are mounted rods 13, 1 1, these rods being provided with These rods between the heads and the ears are provided with springs 16 so as to form a yielding connection. Between the driver heads 15 takes a pin 17 projecting from a driven member 18 which may be in the form of a disk, which is fast on the shaft 7, before referred to, and by which the shaft is driven from the sprocket through the connections just described.

lVith the construction described, having va yielding connection between the loosely running sprocket and the driver, the cylin- 1 der may run with the bed at speeds which are slightly increased or decreased relatively to the speed of the driving mechanism. this speed-being controlled by the plate on the bed, the cylinder running with the plate slight increase or decrease in the diameter of the'cylinden- The springs furthermore act to reposition the cylinder after each revolution of the bed, this being necessary due to the fact that the cylinder, being slotted to receive the blanket clamp, must always take on the bed at substantially the same point at each reciprocation of the bed.

lVhile the invention has been shown and described in its preferred form, it will be understood that certain variations may be made in thespecific construction by which the results aimed at are accomplished, and it is understood that such changes and variations may be made without departing from the invention. 1

WVhat is claimed is:

In a plate printing machine, the combination with a driven bed, of an impression cylinder cooperating therewith, a driver sprocket loosely mounted on the cylinder shaft, a driven disk fast on the cylinder shaft, a pin on the disk, and spring-seatedv heads on the sprocket between which the pin takes, whereby the. cylinder may have a slightly increased or decreased speed relatively to the speed ofthe sprocket.

In testimony whereof, I have hereunto set my hand.

1 OSCAR ROESEN.

Witnesses: r

RICHARD KELLY, v HAROLD M. TILLINGHAST.

Copies of this patent may be obtained for five cents each. by addressing the.Commissioner of Patents,

. Washingtonfl). C. 

